Just inherited a m35a2 and need some assistance.

[rustystud]

Rusty, what do you consider to be over revving? I am somewhat new to driving the deuce, and always downshift and take advantage of engine compression braking.

What gimpyrobb said. Don't go over 2200 RPM's. Remember that your engine is being stressed differently when used to brake versus being powered by itself (compression firing in the cylinders) . Think connecting rods being "pulled" instead of "compressed" .

 

[RodUSMC1962]

We were always trained to gear down when coming to a stop, only used brakes for the final stop. Maybe other services were trained to not do this.

 

[daytonatrbo]

What gimpyrobb said. Don't go over 2200 RPM's. Remember that your engine is being stressed differently when used to brake versus being powered by itself (compression firing in the cylinders) . Think connecting rods being "pulled" instead of "compressed" .

The connecting rods are never pulled. There's no throttle plate, theres no engine braking by vacuum.

The engine braking happens when the pistons compress the intake charge, but there's insufficient fuel for a combustion event, so theres no power added to the crank, only lost to pumping.

 

[mobileauto2000]

Unless the turbo is producing enough boost to offset, the cylinders (not intake) are under vacuum on the intake stroke. A piston going down pulls more air than an intake valve can flow. I know I am nitpicking, also just going down the rods are pulled buy piston and cylinder wall friction. Again as long as the boost is low enough not to push down on the piston. Again nitpicking.

 

[rustystud]

The connecting rods are never pulled. There's no throttle plate, theres no engine braking by vacuum.

The engine braking happens when the pistons compress the intake charge, but there's insufficient fuel for a combustion event, so theres no power added to the crank, only lost to pumping.

When there is no "charge" of fuel then what is making the rods go down ? It's from the crank which is basically "pulling" the pistons down. I learned this in "Tech" college, Engines 101 . This is also used as a diagnostics tool when trying to find loose wrist pins on pistons. The engine will make a different sound and the wrist pins will make a noise that can be heard.